Internal wall insulation is a way of adding a thermal layer to the exsisting walls of your home. Plasterboard with various thicknesses of insulation attached to it. It is fixed to the wall with drylining adhesive or fixed to a frame. In older properties with no cavity a frame is fixed to the wall and a vapour barrier is fitted to stop any condensation from affecting the plaster boards which also have a vapour barrier already attached to them. The plasterboards are then skimmed ready for decoration.